The present invention relates to adjustable seating in which a seat back and seat bottom move relative to a frame.
Adjustable seating of this type, which is disclosed in U.S. Pat. No. 5,108,149, has a frame that includes a seat-supporting portion and a back-supporting portion, a seat bottom mounted on the seat-supporting portion for sliding movement between rearward and forward positions, and a seat back mounted on the back-supporting portion by a resilient articulating linkage for tilting movement independently of the position of the seat bottom between a resiliently restrained upright position and a tilted-back position. The seat back is mounted on an upper linkage member of the resilient articulating linkage so that the seat back can slide downwardly or upwardly relative to the back-supporting portion. A compressed coil spring engaged between the seat back and the back-supporting portion of the frame yieldably biases the seat back to an upward position. A coupling member connects the seat back to the seat bottom.
The adjustable seating of U.S. Pat. No. 5,108,149 functions such that a person sitting in it can change his or her sitting posture between an upright position and a reclined posture (leaning back). When the seat bottom slides forward or backward, the seat back also moves up or down. Therefore, the person sitting in the chair can take a relaxed posture. With this arrangement, there is provided an advantage of not causing pulling and rumpling of clothing because of no relative movement between the person's back and the seat back. In addition, the back region of the person sitting in the chair is well supported in the relaxed position.
However, total comfort is not provided because the whole lumbar region is not well supported at any time due to a substantial space existing between the seat bottom and the seat back.